Abstract
A review and reanalysis of geological, molecular, and paleontological data led O'Dea et al. (1) to propose (i) that reports by Montes et al. (2) and Bacon et al. (3) regarding a middle Miocene closure of the Central American Seaway (CAS) are unsupported, and (ii) a new age of the formation of the Isthmus at 2.8 million years ago (Ma). Here, we reject both of these conclusions.